1. Technical Field
The present invention relates to a cam crank mechanism serving as a small and light power transmission mechanism for converting rotational movement into reciprocable movement. Further, the present invention relates to a portable motor driven hydraulic tool including a battery as a power supply source and a cam crank mechanism of the foregoing type preferably employable for a cable laying operation.
2. Statement of the Related Art
To perform a cable laying operation, various kinds of hydraulic tools for collapsing a terminal or sleeve for connecting conductors to each other or cutting a conductor or cable have been heretofore used by operators. The conventional hydraulic tool is typically constructed such that a hydraulic pump adapted to be driven by an engine or motor is placed on the ground and a pressure resistant hose extends between the hydraulic pump and a tool head carried by an operator which performs a cable laying operation at a high position. The hydraulic pump feeds pressurized hydraulic oil to the tool head including a stationary die and a movable die to collapse the terminal or sleeve between the both dies for connecting conductors to each other.
Also a manual hydraulic tool of the type having a hydraulic pump incorporated therein has been known. This type of hydraulic tool is used for a cable laying operation in such a manner that an operator repeatedly actuates an actuating lever by his hand to increase hydraulic pressure of hydraulic oil and the increased hydraulic pressure displaces a movable tool member toward or away from a stationary tool member to collapse a terminal or sleeve for connecting conductors to each other.
However, it has been found that the conventional hydraulic tool of the first-mentioned type has drawbacks that an operator performs a cable laying operation with much difficulties due to extension of the pressure resistance hose and moreover the heavy hydraulic pump should be displaced at every time when he changes his work location. Thus, a cable laying operation is accomplished at a very low efficiency.
Also with respect to the hydraulic tool of the last-mentioned type, it has been pointed out as a problem that it does not use any pressure resistant hose but the tool head requires a high intensity of hydraulic pressure which is generated by an actuating lever to be actuated by an operator's hand, causing the operator to be tired as the lever is repeatedly actuated.